Broken-down-insulating-joint protection.



S. M. DAY. BROKEN DOWNINSULATING JOINT PROTECTION.

APPLICATION r1120 SEPT. 15, 1912.

' Patented May 2,1916.

INVENTOI? M 97;. 92 W Wi [IQW 111M 111M111.

THE COLUMBIQ PLANOGRAPH c0., WASHINGTON, D. C.

onnro.

SALISBURY M. DAY, OF ROCHESTER, NEW YORK, ASSIG-NOR TO GENERAL RAILWAYSIGNAL COMPANY, OF GATES, NEW YORK, A CORPORATION OLE NEW YORK.

Specification ofjLetters Patent.

Patented May 2, 1916.

Application filed September 6, 1912. Serial No. 718,838.

This invention relates to railway electric track circuits.

The primary object of this invention is to furnish means whereby a breakin the means for guarding against the dangerous effects of broken downinsulating joints will be indicated immediately.

Another object of the invention is to provide means for indicating theexistence of a break of any nature whatsoever, in an insulating joint.

Other objects and as the description of the invention progresses, andthe novel features of the inven tion will be particularly pointed out inthe appended claims.

The ordinary and well known track circuit section is commonlyconstructed with a source of electro-motive force connected across therails at one end of the section, and a translating device connected.across the same rails at the other end of the same section, and adjacentsections are separated one from the other by means of what is known asan insulating joint, which con sists essentially of a fiber memberinterposed between the abutting rail ends of the two sections, and fiberplates interposed between the ordinary and well known splice plates andthe rails, together with the suitable devices for properly preventingthe bolts used for holding the whole together from coming in contactwith the metal of both a rail and a splice plate.

As ordinarily constructed, if any defect occurs in any of the insulatingmaterial used, a conducting path for electricity may exist between therail of one section and the rail of an adjacent section. In case onlyone joint breaks down there will probably be no injurious effect in thecase of steam road direct current or alternating track circuits, but ifboth joints break down or in the case of track circuits employingreactance bonds if only one joint breaks down, then the source ofelectro-motive force connected advantages will appear across the railsat the end of one section can cause a flow of current to the relayconnected at the proximate end of the adjacent section and,consequently, although the relay in the adjacent section should bedeenergized, by reason of a car in the section to which it is connected,nevertheless it might be energized and probably would be, if the breakdown between the sections was complete, by reason of a-flow of currentfrom the track battery in the adjacent section. Such a condition, ofcourse, is extremely dangerous. Various means for remedying thepossibility of such a dangerous failure have been devised. The methodmost commonly used is to reverse the polarity of the leads from thesource of electro-motive force to the rails of the track sections inadjacent sections. This method is not, however, applicable to theordinary battery fed track section employing a neutral relay asatranslating device, for such a relay is op erably energizedirrespective of the direction of the current flow therethrough. Themethod is, however, applicable if usedin connection with track circuitsections fed from a source of alternating current and in which thetranslating device is constructed in the form and in accordance with theprinciple of the well known induction motor havin a stator with twowindin s thereon and a squirrel cage armature, because current flowingto the induction motor relay will cause a movement of the armature ofthe induction motor in one direction when fed thereto from the propertrack circuit section, but will cause a reverse movement of the armaturewhen fed to the induction motor from the source of current connected tothe track rails of the adjacent section. Even when alternating currentis employed for feeding the track circuit sections, it is impossible toobtain the above mentioned method of operation under all conditions,because when what is known as the wireless track circuit is employed, asis well known to those skilled in the art, the polarity of the currentsupplied to the track rails of the track circuit sections is changeddepending upon the position of the semaphore resulting from trainmovement or other causes, so that a broken down joint would allowcurrent to flow from an adjacent section to the relay of the proximatesection at some times in a proper direction to cause a false cautionsignal. It being possible to so arrange track circuit polarities, withwireless control, as to avoid the more clangerous false clearindication. In order to remedy such defects in a track circuit, aconductor has been connected to each of two metal posts which have beenplaced one in each line of rails at the abutting ends of two trackcircuits, and separated from the rails by insulating posts. Thisconstruction protects against a break down due to the creeping of therails, but does not protect against some break downs due to othercauses, furthermore, the entire protection is lost if the conductorbecomes broken. Applicants invention as heretofore stated has as itsmain objects the elimination of such defects.

In describing the invention in detail, reference is had to theaccompanying drawings, wherein I have illustrated a preferred physicalembodiment of my invention, and wherein like characters of referencedesignate corresponding parts throughout the several views, and in whichFigure 1 is a schematic representation of the ordinary track rails andinsulating joints at the abutting ends of two direct current trackcircuit sections, together with sources of electro-motive force and atrans lating device as commonly constructed, with applicants inventionapplied thereto; Fig. 2, is a schematic representation of the ordinarytrack rails and insulating joints at the abutting ends of twoalternating current track circuit sections employing balanced reactancebonds, together with sources of electro-motive force and a translatingdevice as commonly constructed for electrically propelled railways, withapplicants invention applied thereto.

Referring to Fig. 1, numerals 1, 2, 3 and 4 designate the ordinary andwell known rails of a railway track; 5 and 6 designate generally aninsulating joint which is in the main, identical with the well knownforms of insulating joints, as will readily be perceived by thoseskilled in the art of railway signaling. It consists of insulatingplates 7 which separate the splice plates 8 and 9 from contacting withthe rails 1 and 2 or 3 and 4, and it further consists of bolts 10 and 11which bind the plates 7, 8 and 9 and the rails 1 and 2 and 3 and 4tightly together. In order to separate the ends of the rails 1 and 2 and3 and 4, one from the other, the end posts 12 and 13 employed are madefrom insulating material and have placed therebetween the conductingmember 14. The sources of current 16 and 15 are shown connected acrossthe rails of the sections A and B respectively and a translating device17, including the armature 18,

* which controls a signal mechanism-not shown-is delineated connected tothe section B. The connections of the sources of current are as usual.One terminal of the translating device 17 is also connected, as isusual, to one of the track rails, in this case 4; the other terminal ofthe translating device 17 is connected to the splice plate 9, which inturn is connected by means of the conductor 19, with the splice plate 8;splice plate 8 is connected by means of the conductor 20 with theconducting member 14, the' conductor 27, splice plate 9, conductor 19,

splice plate 8, conductor 20, conducting member 14, conductor 21,conducting member 14 on the other side of the track, conductor 22,splice plate 9, conductor 23, splice plate 8, conductor 24, rail 2 andconductor 28 to the other terminal of the source of current. The currentflowing through the above traced path of course energizes thetranslating device 17 and causes the armature 18 to be held in its upperposition so that the signal controlled thereby would as is wellunderstood by those skilled in the art, be moved to and held in itsclear position.

The arrangement as shown in Fig. 2, is that which would be used upon anelectrically propelled railway where the ordinary and well known form ofbalanced reactance 1 bonds were used to allow propulsion current to flowfrom block section to block section.

Numerals l, 2, 3 and 4 designate the rails of the trackway as in Fig. 1,and 7 designates fiber insulating plates which prevent splice plates 8and 9 from coming in contact with the rails. The fiber plates and spliceplates are held in place, as in Fig. 1, by bolts 10 and 11. Fig. 2 alsoshows the conducting posts 14 interposed in both lines of rails andseparated from the ends of the adjoining rails by means of theinsulating pieces 12 and 13 just as in Fig. 1. The splice plates 8 and9, applied to the upper rail, are connected together by conductor 19 andthose applied to the lower rail are connected together by the conductor23.

The alternating current required with a system of signaling on anelectrically propelled road is here shown as supplied by means oftransformers 36 and 37. The sec ondary winding of 36 is connected bymeans of wires as 31 and 32 to the two track rails 2 and 4, and thesecondary winding of 37 by means of wires 56 and 57 to rails 1 and 3.

Another transformer 38 supplies current to one winding of the inductionmotor type of relay 39, which has the movable member 40 attached, tomake and break a circuit controlling a signal, not shown.

The balanced reactance bond 33 has its ends connected one to each rail,and its center point connected by means of wire 34 to the center pointof a balanced reactance bond 35, the ends of which are connected to therails 1 and 3 in the adjoining block. The reactance bond 33 has the coil41 wound in inductive relation thereto so that the two virtually form atransformer of which the winding 33 is the primary and the winding 41 isthe secondary, and the primary is supplied by current from the secondarywinding 29 of the transformer 36. The complete circuit for the track fedwinding 42 of relay 39 is as follows: one terminal of winding 42, wire43, secondary 41, wire 44, splice plate 9, wire 19, splice plate 8, wire20, conducting post 14, wire 21, conducting post 14 in the other line ofrails, wire 22, splice plate 9, wire 23, splice plate 8 and wire 45 tothe other terminal of the winding 42. Current flowing in the abovetraced path at the same time that current is flowing in the otherwinding of the relay causes the member 40 to make contact so as tocomplete the circuit of the signal.

' It should be noticed that the conductor 21 in Fig. 1, and theconductor 21 in Fig. 2, would each form a path of low resistance for thesources of energy connected to section A if rail 1 should come incontact with post 14 in the lower rail and rail 3 should come in contactwith post 14 in the upper rail. As posts 14 are placed directly in linewith rails 2 and 4, it would be impossible for rails 2 and 4 to abutrails 1 and 3 without also having posts 14 abut rails 1 and '3,consequently, any contact of rails 2 and 4 with rails 1 and 3 must bemade through posts 14, but if such contact is made through post 14, thenthe source of energy in block A has a path of low resistance throughconductor 21 offered to it, so that even if relay 17 were connecteddirectly across rails 2 and 4, and relay 39 were connected directlyacross rails 2 and 4, no current would flow to the relays. Even withconductor 21, however, the connection of relays 17 and 39 directlyacross the rails would render them liable to be affected by broken downinsulating joints if the conductor 21 were broken, or if some other pathfor current from rail 1 to rail 2 and from rail 3 to rail 4 were formedother than that through the conducting post 14.

In the present case the conductor 21 is made a part of the completecircuit of the relay, consequently, if it becomes broken and therebyloses its power of protection, the relay immediately becomes denergizedand by placing the signal at danger with no train in the block, willimmediately cause the defect to be noticed, and by causing the spliceplates to also form part of the complete circuit of the relays, any formof broken down joints will cause a shunt to be placed either upon therelay or upon the source of current in the adjacent block.

An example will serve to show how applicants method protects againstbroken down insulating joints. Referring to Fig. 1, suppose that fishplate 8, attached to the upper rail should become conductively connectedto rail 3, illustrated by thedotted line 45, and the same plate shouldalso become conductively connected with rail 4, illustrated by dottedline 46, and at the same time the splice plate 9, attached to the lowerrail should become conductively connected with rail 1, illustrated bythe dotted line 47, and with the rail 2, illustrated by the dotted line48. Under such conditions a path for the flow of current from the source16 would be formed from rail 1 to rail 2 and from rail 3 to rail 4. Ifthe relay 17 were connected directly across the rails, and theheretofore known method of connecting conductor 21 were employed, itwould be energized by the improper flow of current even if a train werein a remote part of block B, and this would be so even if conductor 21were intact, but in applicants invention, as shown in Fig. 1, thecurrent from the source 16 would flow through wire 49, rail 3, path 45,splice plate 8, wire 20, post 14, wire 21, post 14 in the lower line ofrails, wire 22, splice plate 9, conducting path 47, rail 1 and by meansof wire 50 to the other terminal of the sources of current 16. The relay17 would thus be effectually shielded from the effects of the currentflowing from the source 16 due to the presence of broken down insulatingjoints. At the same time the relay would be denergized due to the factthat a shunt would be formed in which current would flow as follows:source 15, wire 25, rail 4, conducting path 46, splice plate 8,conductor 20, post 14, conductor 21, post 14 in the lower line of rails,wire 22, splice plate 9, conducting path 48, rail 2, and conductor 28 tothe other terminal of the source.

Although one example only has been given, it will be found that anycombination of conducting paths which would allow current to flow to therails of one block from a source connected to the rails in an adjoiningblock would cause either a path of low resistance to be formed for theimproperly flowing current or a shunt to be formed upon the relay orboth.

If the arrangement as shown in Fig. 2, is considered, the same resultswill be shown as pointed out in Fig. 1. As an example, consider thatsplice plate 8 is connected by conducting path as 52 Wit rail 3, and. by

conducting path as 53 with rail 4, and that splice plate 9 in the lowerline of rails is connected by means of a conducting path as 54 with rail1 and by means of conducting path 55 with rail 2. If the winding 42 ofrelay 39 were connected directly across rails 2 and 4 then current wouldflow from the primary 30 of transformer 37 to the winding 42 and thiswould be so even if conductor 21 were intact. In applicants arrangement,however, such a condition would not result in the energization ofwinding 42 because a path for the current from secondary 30 would beformed as follows: one terminal of secondary 30, wire 56, track rail 3,conducting path 52, splice plate 8, wire 20, conducting post 14-,conductor 21, conducting post 14 in the lower line of rails, conductor22, splice plate 9 and conducting path 54, rail 1, and by conductor 57to the other terminal of secondary 30. At the same time the followingcircuit would be formed, secondary 29, wire 31, rail 4, conducting path53, splice plate 8, wire 20, conducting post 14, conductor 21,conducting post 14.- in the lower line of rails, conductor 22, spliceplate 9, conducting path 55, rail 2, and conductor 32 to the otherterminal of the secondary 39. The existence of either of the abovetraced paths would prevent an energization of winding 12 either from thesource in the block A or from the proper source in block B.

The arrangement shown by Fig. 2 has the further advantage not possessedby the arrangement of Fig. 1, namely: the breaking down of one jointwill render inoperative both track circuits which abut at the joint; andthe partial breaking down will. render one track circuit inoperative. Ifrail 1 comes in contact with post 1 1, then the lower half of bond 35will be shunted, which will be equivalent to so reducing its impedanceto the current flowing from primary 30, as to allow so much current toflow locally that the translating device-not shownat the other end ofthe section will not receive sufficient current to operate it. If rail 2comes in contact with post 14, then the lower half of bond 33 will beshunted, under which condition secondary 4-1 will not be sufficientlyenergized to operate relay 39.

If rails 1 and 2 both contact with post let both of the abutting trackcircuits will become inoperative. lVith systems as commonly used inwhich the relays are connected directly across the track rails, withoutthe post 14; and conductor 21, and without applicants invention, it rail1 should come in contact with rail 2 then current would flow from wire57, through rail 1, rail 2, bond 33, wire 34:, bond 35, rail 3 and wire56 to the primary of transformer 30. In such case by auto-transformeraction the voltage across the terminals of bond 33 would be raised, andconsequently the relay in section B would be falsely operativelyenergized.

The particular and specific physical instruments herein shown asembodiments of applicants means in no Wise exhaust the various physicalforms in which it may be embodied, because many other forms are nowknown to the applicant, and furthermore, many different forms willimmediately suggest themselves to those skilled in the art;nevertheless, applicant desires to have it understood that he considersall such forms to be within the scope of his invention as defined by theclaims.

IV hat I claim as new and desire to secure by Letters Patent of theUnited States, is:

1. In railway electric track circuits; two lines ofelectricallyconductive rails forming a trackway; means for dividing said trackwayinto electrically independent track circuit sections; a. source ofelectro-motive force connected between the rails of each section; meansto prevent current from one section flowing to the rails of an adjacentsection when the corresponding rails of ad jac'ent sections come intoelectrical contact with each other; a translating device in each sectionincluding said last mentioned means in its operating circuit andenergized bythe source of electro-motive force connected between therails of the same section.

2. In a railway electric track circuit; two lines of electricallyconductive rails forming a trackway; insulating joints composed ofelectrically conductive members and in sulating members, and each havingan electrically conductive post situated in line with the rails butelectrically separated therefrom, said joints being interposed in eachline of rails, at intervals, forming electrically independent trackcircuit sections; an electrical conductor joining the posts of thecorresponding joints; translating devices each in a circuit includingthe corresponding posts adjacent thereto, said electrical conductor, andsaid electrical conductive members of the corresponding insulatingjoints; a source of electro-motive force connected between the rails ofeach section at a point remote from the translating devices in eachsection for energizing said translating devices.

3. In a track circuit for railways, in combination with the trackrailsof the traclc way, an insulating joint in each of said track rails anddividing said track rails into electrically isolated sections, a trackcircuit for each of said sections, a conductor of low resistanceadjacent to said insulating joints and normally disconnected from saidtrack rails, said conductor being included in one of said trackcircuits, and means for electrically connecting the ends of saidconductor to Said track rails when the corresponding ends of said trackrails separated by said insulating joints come into electrical contact.

4:. In a track circuit for railways, two lines of electrical conductiverails forming a trackway, an insulating joint in each line of rails andcomprising a body ofinsulating material interposed between the adjacentends of the rails of that line, each of said joints also comprising twosplice plates secured to the corresponding line of said rails andinsulated therefrom, and electric conductors of low resistanceconnecting both of said splice plates of both of said joints in series.

5. In a track circuit for railways, two lines of electrically conductingrails forming a trackway, a source'of current associated with said linesof rails, an insulating joint in each of said lines of rails comprisingabody of insulating material interposed between the adjacent ends of therails of that line, a metallic post inclosed in each of said bodies ofinsulating material in line with the corresponding line of rails andinsulated therefrom, a conductor of low resistance electricallyconnecting said posts, a translating device, and a circuit for saidtranslating device including said conductor.

6. In a track circuit for railways, two lines of electrically conductingrails forming a trackway, a normally closed track circuit associatedwith saidlines of rails, and including a source of current, aninsulatingjoint in each of said line of rails comprising splice platesfastening said rails together and insulated therefrom, and a metallicpost interposed between the adjacent separated ends of the rails andinsulated from said rails and from the corresponding splice plates, saidsplice plates and said posts of said joints being electrically connectedin series with said track circuit.

7 In a track circuit for railways, two lines of electrically conductingrails forming a trackway, a pair of insulating joints in said lines ofrails each comprising a metallic post interposed between the adjacentseparated ends of said rails and insulated therefrom, an impedance bondon each side of Copies of this patent may be obtained for five centseach, by addressing the said pair of joints and connected across saidrails, a conductor between the middle points of said impedance bonds andanother conductor connected to said first-mentioned conductor and tosaid posts, whereby the breaking down of the insulation between one ofsaid rails and its corresponding post will short-circuit one-half of thecorresponding impedance bond.

8. In a signaling system for railways, in combination with the trackrails of a trackway, insulating joints arranged in pairs and dividingsaid track rails at intervals into electrically independent tracksections, a source of current and a relay associated with each tracksection, a conductor of low resistance adjacent to each pair of saidinsulating joints and normally disconnected from said track rails,'andmeans for electrically connecting the ends of said conductor to saidtrack rails when the corresponding track rails of adjacent tracksections come into electrical contact.

9. In a signaling system for railways, in combination with the trackrails of a trackway, insulating joints arranged in pairs and dividingsaid track rails at intervals into electrically independent tracksections, each of said insulating joints comprising splice platesfastening said rails together and insulated therefrom, a metallic postinterposed in each joint between the ends of the corresponding trackrails and insulated therefrom and from said splice plates, an impedancebond on each side of each pair of joints and connected across the trackrails, a conductor between the middle points of said impedance bonds,another conductor connected to said first'mentioned conductor and tosaid posts of the corresponding joint, a translating device associatedwith each pair of joints and a circuit for said translating deviceincluding in series said splice plates, said posts of that pair ofjoints and the corresponding second-mentioned conductor.

SALISBURY M. DAY.

Witnesses:

LILLIAN L. PHILLIPS, L. MUTSCHLER.

"Commissioner of Patents.

Washington, D. G.

